When dispensing pesticides and other biological-treatment agents from aircraft, physical factors, such as aircraft speed, spraying height, spray pressure, flow rate, and swath width are all major factors affecting the degree of target coverage and dosage for a given formulation, concentration and nozzle size. The coverage, dosage, and pesticide stability determine the degree of mortality; therefore it is desirable to monitor and control the above factors.
Pesticide applicators calibrate the flow rate from their spray systems based on the following factors: (1) application rate (volume/unit area), (2) swath width, and (3) spray speed. The applicator assumes that these parameters remain constant throughout the spray job, when in fact they do not. When the spray pressure varies, the flow rate and degree of atomization also vary, which in turn alters the application rate.
Among important factors in particular to be monitored are spray pressure and liquid flow rate, since these provide information as to whether the spray nozzles are working properly. Also it is important for the pilot to monitor in real time the other spray parameters, such as total liquid volume dispensed, total spray passes, total spray time, ambient relative humidity, air temperature, and dispensed liquid temperature.
In the prior practice it was almost impossible for a pilot to observe all the above required factors and still perform accurate spray application within the very small time span of the application.
Therefore there is a need for improved equipment for monitoring spray application parameters so as to improve the ability to compare pesticide efficacies, determine the efficiency of performance of the spray equipment, and generally to alleviate pilot stress.
Previously employed systems have included a flow metering device which records the total liquid volume on an electro-mechanical counter and gives instantaneous flow rate on a meter. In the prior systems no permanent recording of the flow rate versus time is available, nor do these prior systems have provision for recording liquid pressure and spray passes, or for spray time data gathering.
A preliminary search of the patented prior art revealed the following prior U.S. Pat. Nos. of interest:
Ripper: 2,941,753 PA1 Cornett: 3,476,337 PA1 Johnson: 3,484,062 PA1 Zimmerman et al: 3,839,911 PA1 Zimmerman et al: 3,802,261 PA1 White et al: 3,934,471 PA1 Honey: 3,965,341